Definitely drop the 'Evil' prefix, and the kind of squad I'd like to see Magneto assemble is a real powerhouse team that definitely feels like its ready to rise up and can go toe to toe with any Avengers or X-Men team that come their way.
Magneto
Briar Raleigh
Blob
Danger
Daken
Dark Beast
Elixir
Exodus
Frenzy (Or Monet)
Magik
Mystique
Polaris (Kinda want to include Lorna as a 'positive' influence, in the same vein that Storm stuck around with the extinction team. Lorna is here to make sure no one goes too rogue)
Stepford Cuckoos (Or Quentin Quire)
Toad
Unuscione
Vanisher
I appreciate the mix of villain, anti-hero and ostensibly hero in this line up, whilst also catering to a variety of eras and generations.